Is it possible to give rules of the following kind: Every field of type INTEGER will take N bytes (N=4?), every field of type VARCHAR(X) will take I*X+J bytes (I, J =?), every field of type VARCHAR with NULL value will take K bytes, every row will take the sum of all field-widths plus L bytes,
I think it *is* possible, but I'm not aware of anyone who has done this. When I was faced with practical problems of this sort (how much space will my database take up, if I design the tables like this?), my approach was to prototype the tables, load up a "reasonable" amount of data (at least a few hundred thousand rows, maybe a million rows), and look to see how much actual space got used. The Derby "SPACE_TABLE" tool is quite useful for running experiments like this. http://db.apache.org/derby/docs/10.8/ref/rrefsyscsdiagtables.html thanks, bryan
